A Research On Platinum And Nickel-based Enzyme-free Glucose Sensors

Objective:In recent years,with the increasing incidence of diabetes,diabetes and its complications have increasingly become a disease threatening human health and affecting people's quality of life.For diabetics,controlling level of blood sugar is an important thing at any moment,so monitoring their blood sugar concentration becomes an important part of their daily life.The purpose of this study is to develop an efficient,convenient and reliable enzyme-free glucose sensor for real-time,long-term and accurate monitoring of glucose.Methods:1.NiNPs were electrodeposited on graphene modified GC electrodes by cyclic voltammetry using a three-electrode system at room temperature to construct an enzyme-free glucose sensor.The effects of the concentration of Ni precursor,the pH value of the deposit solution and the number of cyclic voltammetric cycles on the catalytic oxidation ability of the enzyme-free glucose sensor were investigated.Finally,the enzyme-free glucose sensor modified by NiNPs was constructed under the optimum conditions.The current curves of the sensor in different concentration of glucose solution were recorded by chronoamperometry to study its catalytic oxidation ability to glucose,including linear response range,detection limit,response time and sensitivity.The selectivity,long-term stability and repeatability of the sensor are further studied.2.At room temperature,Pt and Ni were electrodeposited on graphene-modified GC electrode by cyclic voltammetry using a three-electrode system to construct an enzyme-free glucose sensor based on PtNi nanoalloy.The effects of Ni and Pt precursor concentration,electrolyte types and cyclic voltammetric cycles on the catalytic oxidation of glucose by the enzyme-free glucose sensor were investigated.Finally,an enzyme-free glucose sensor modified by PtNi nanoalloy was constructed under the optimum conditions.The current curves of the sensor in different concentration of glucose solution were recorded by chronoamperometry to study its catalytic oxidation ability to glucose,including linear response range,detection limit,response time and sensitivity.The selectivity,long-term stability and repeatability of the sensor are further studied.Result:1.The experiments show that pH 4.0,concentration of Ni precursor 20mM and cyclic voltammetric cycles 45 are the optimum conditions for depositing NiNPs.NiNPs/rGO/GC electrodes were prepared under the optimum conditions and showed high catalytic activity for glucose.The linear range of the sensor for glucose detection is 1uM¹0mM,the sensitivity is 1178uAmM^1-cm^2-,and the low detection limit is 1uM.In addition,the enzyme-free glucose sensor has good anti-interference to AA,UA,DA,and fast response speed?about 3s?.2.Experiments show that the optimum conditions for PtNi nano-alloy deposition are sodium sulfate,20 mM Ni precursor concentration,5 mM Pt precursor concentration and 25 cycles of cyclic voltammetry.In this paper,PtNi/rGO/GC electrodes were prepared under the optimum conditions,which showed high catalytic activity for glucose.The linear range of the sensor is 0.02⁹ mM,the sensitivity is 12.45 uAmM^1-cm^2-,and the detection limit is 0.02 mM.